Introduction

Both paroxysmal high-grade second-degree and persistent third-degree atrioventricular block (AVB) are recognised in cats. Our aim was to document the presentation, echocardiographic data, comorbidities and outcome in affected cats from a single referral hospital, including those that underwent epicardial pacemaker implantation (EPI).

Animals, materials and methods

This retrospective study included 64 cats diagnosed with persistent third-degree or paroxysmal high-grade AVB, for which detailed patient history was available. Non-parametric testing, Kaplan-Meier curves and Cox proportional hazard testing were performed.

Results

Atrioventricular block was persistent in 43 cats (67%) and paroxysmal in 21 (33%). Forty-seven cats (74%) were referred for cardiac complaints (e.g. collapse, arrhythmia, tachypnea), 6 (9%) had non-specific complaints and AVB was an incidental finding in 11 cats (17%). Median duration of clinical signs prior to presentation was 21 days (1–1138 days). Thirty-nine (63%) cats had echocardiographic abnormalities; 13 (20%) presented with congestive heart failure. Forty-five (70%) cats had one or more comorbidities. Fifteen cats underwent EPI with immediate resolution of signs in 12 cats. Following EPI, two and four cats experienced major and minor complications, respectively. Forty-seven cats died; median survival time was 799 days (all-cause mortality). Cardiac-related death occurred in 17 cats (36%); median survival in these cats was 132 days. Heart failure on presentation was the only independent risk factor for cardiac death (p=0.002).

Conclusions

Outcome in cats with AVB was variable, although most had good medium- to long-term survival. Cardiac death occurred in a minority of cats. Pacemaker implantation was effective in relieving clinical signs.

中文翻译：

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猫的阵发性高度二度和持续三度房室传导阻滞

介绍

阵发性高级别二度和持续性三度房室传导阻滞（AVB）在猫中均被识别。我们的目的是记录来自一家转诊医院的受影响猫的表现、超声心动图数据、合并症和结果，包括那些接受心外膜起搏器植入 (EPI) 的猫。

动物、材料和方法

这项回顾性研究包括 64 只诊断为持续性三度或阵发性高级别 AVB 的猫，可获取详细的患者病史。进行了非参数检验、Kaplan-Meier 曲线和 Cox 比例风险检验。

结果

房室传导阻滞在 43 只猫 (67%) 中持续存在，在 21 只猫 (33%) 中呈阵发性。47 只猫 (74%) 因心脏问题（例如虚脱、心律失常、呼吸急促）而转诊，6 只 (9%) 有非特异性问题，AVB 是 11 只猫 (17%) 的偶然发现。就诊前临床症状的中位持续时间为 21 天（1-1138 天）。三十九 (63%) 只猫有超声心动图异常；13 (20%) 名出现充血性心力衰竭。四十五 (70%) 只猫有一种或多种合并症。15 只猫接受了 EPI，12 只猫的症状立即得到解决。在 EPI 之后，两只和四只猫分别出现了严重和轻微的并发症。四十七只猫死了；中位生存时间为 799 天（全因死亡率）。17 只猫（36%）发生心脏相关死亡；这些猫的中位生存期为 132 天。p = 0.002）。

结论

患有 AVB 的猫的结果是可变的，尽管大多数都有良好的中长期存活率。少数猫发生心脏死亡。起搏器植入可有效缓解临床症状。